Just installed 1.1.6.3 today. Q: How exactly does a Wikka adminstrator change the rights to a page that has been made public?

Erik, click the "Edit ACLs" link at the bottom of the page (or, append "/acls" to the page URL to navigate directly to the ACLs for that page). From here, you can modify ACLs as well as ownership.

Also, you can set default read/write/comment ACLs in your wikka.config.php file.

The "Edit ACLs" was never displayed, and by appending the URL I'm getting the error "You are not the owner of this page" even though I am logged in as the administrator. :-/

Then you must not be logged in as an administrator :) Does "You are..." appear in the upper right? If it does, then check your wikka.config.php file and make sure the "admin_users" parameter is set correctly.

Follow up: I had delineated my 'admin_users' in wikka.config.php with the "\n" code instead of with commas. I mistakenly took this cue from what's required for 'default_..._acl' All better now!